ITT 



JUB 



The process followed by Vauquelin to 

 obtain this earth from the gadolinite was, to 

 dissolve it, with the assistance of heat, in 

 diluted nitric acid, pouring 1 off the solu- 

 tion from the undissolved silex. The 

 liquor is then evaporated to dryness, by 

 which any remaining' silex and any oxide 

 of iron is separated from combination 

 with the acid. By redissolving the resi- 

 duum in water, the compound of nitric 

 acid and ittria is obtained : if there are 

 any traces of iron, the liquor is either 

 aga'ui evaporated to dryness, or a little 

 ammonia is added ; and after the separa- 

 tion of the oxide of iron by yellow flakes, 

 the solution is decomposed by ammonia, 

 which precipitates the new earth. (Philo- 

 sophical Magazine, vol. viii. p. 369.^ The 

 process employed by Klaproth is similar, 

 nitro-nnmatic acid being employed ; the 

 iron being removed by the action of suc- 

 cinate of soda ; and the ittria being pre- 

 cipitated by carbonate of soda. (Analyti- 

 cal Essays, vol. ii. p. 47.) 



Ittria is obtained in the form of a white 

 powder, and is heaver than any other 

 earth ; its specific gravity according to 

 Ekeberg being 4 842. It is not fusible 

 alone, but with borax it forms a white 

 glass. It is not soluble in water, but it 

 retains that fluid with considerable force. 



Ittria combines with the acids; its salts, 

 as has beeu remarked, having generally a 

 sweetish taste. Several of them, too, are 

 coloured, a property iu which it differs 

 from all the other earths. 



The sulphate of ittria crystallizes in 

 small brilliant grains, according to Klap- 

 voth, of a rhomboidalform, and of a colour 

 inclining to an amethyst red. Their taste 

 is sweet, becoming also astringent. They 

 require from twenty-five to thirty parts 

 of water, and are not more soluble in hot 

 water. Their specific gravity is 2.79. 

 The sulphuric acid is expelled by a red 

 heat. Nitrate of ittria can scarcely be 

 crystallized ; it assumes a gelatinous con- 

 sistence by evaporation, and becomes 

 brittle when this jelly cools. Its taste is 

 similar to that of the sulphate. The mu- 

 riate is obtained nearly in the same form. 

 The phosphate, formed by complex affi- 

 nity, is insoluble. The acetite is a crys- 

 tallizable salt of a pale red colour. 



The salts of ittria are decomposed by 

 the three alkalies, and by lime, astronti- 

 tes, and barytes. 



Ittria is not dissolved by the liquid alka- 

 lies, nor do they redissolve it when added 

 in excess, after having precipitated it from 

 its solutions. This affords a distinguish- 

 ing character between it and giucine. 



It is soluble in the alkaline carbonates, 

 particularly in the carbonate of ammonia. 



Prussiate of potash throws down from 

 its solution a granular precipitate, of a 

 white or pearl-grey colour. It is also pre- 

 cipitated in grey flocculi by the watery 

 or spirituous infusion of galls ; but very 

 slightly by the pure gallic acid. It is not 

 affected by sulphuretted hydrogen, or 

 hydro-sulphuret of ammonia, added to its 

 solutions. 



The great specific gravity of this earth, 

 its forming coloured salts, and being pre- 

 cipitated by the alkaline prussiates, and 

 by tannin, from its solutions, in some 

 measure connect it with the metals, and 

 lead to the suspicion that it may be a me- 

 tallic oxide. 



The gadolinite is the only fossil that 

 can be considered as belonging to the ge- 

 nus of wliich this earth is the base, for the 

 yttrotantalite contains it in small quantity 

 only, and is properly a metallic fossil be. 

 longing to the genus Tantalium. The 

 gadolinite occurs massive, and dissemi- 

 nated ; its colour is a deep greenish black. 

 Its internal lustre is resplendent ; it is 

 opaque ; its fracture is conchoidal ; its 

 hardness is such, that it is not scratched 

 by th.e knife ; its specific gravity is 4.2. 

 It intumesces before the blow-pipe, but 

 is not fused. With nitric acid it forms a 

 gelatinous solution. According to Klap- 

 roth, it consists of ittria 59.75, silex 21.25, 

 oxide of iron 17.5, argil 0.5, water 0.5. 

 The analysis of it by Ekeberg and Vau- 

 quelin, give the proportion of ittria rather 

 less, and of silex and iron somewhat more. 



IVA, in botany, a genus of the Monoe- 

 cia Pentandria class and order. Natural 

 order of Composite Nucamentacese. Co- 

 rymbiferse, Jussieu. Essential character : 

 male, calyx common, three-leaved; co- 

 rolla of the disk, one-petalled, five -cleft; 

 receptacle with hairs or linear chaffs fe- 

 male, in the ray, five, or fewer ; corolla 

 none; styles two, long; seeds naked, 

 blunt. There are two species, viz. 1. an- 

 nua, annual iva, and I. frutescens, shrubby 

 iva, or bastard Jesuits' bark tree. 



JUBILEE, a time of public and solemn 

 festivity among the ancient Hebrews. 

 This was kept every fiftieth year : it be- 

 gan about the autumnal equinox, and was 

 proclaimed by sound of trumpet through- 

 out all the country. At this time all slaves 

 were released, all debts annihilated, and 

 all lands, houses, wives, and children, 

 however alienated, were restored to their 

 first owners. During this whole year, all 

 kind of agriculture was forbidden, and 

 the poor had the benefit of the harvest. 



